Coarse-Grained Simulations of Protein Backbone Dynamics. 1. Local Sterics Define the Dihedral Angles

Area of Science:

• Computational Biology
• Biophysics
• Protein Dynamics

Background:

• Simulating unfolded or intrinsically disordered proteins (IDPs) presents challenges due to their conformational flexibility.
• Existing models may lack the efficiency for long protein chains or the resolution for local dynamics.

Purpose of the Study:

• To introduce a novel hierarchical coarse-grained model for implicit solvent simulations of IDPs.
• To enable efficient and accurate modeling of both local and global protein characteristics.

Main Methods:

• A hierarchical model with nonspherical building blocks was implemented.
• Local dynamics are reproduced using harmonic bonds and steric interactions.
• Global chain shape and secondary structure biases (hydrophobic, hydrogen bonds, dipole-dipole) are incorporated.

Main Results:

• The model accurately reproduces local backbone dynamics.
• It captures the global shape of protein chains.
• The hierarchical approach balances near-atomistic local resolution with computational efficiency.

Conclusions:

• This coarse-grained model offers an efficient yet detailed approach for simulating unfolded and intrinsically disordered proteins.
• It provides a foundation for future studies incorporating more complex interactions and larger biological systems.